Castling Into It
by The Wanderlust
Summary: The serial killer from "Tick Tick Tick" and "Boom!" returns to target Castle! I intend to write a second part, as this ends in a cliffhanger. This is my first published fanfic so please review, I could use constructive criticism.


Ryan and Esposito were arguing.

"Haven't you guys got work to do, or something?" snapped Beckett after about five minutes.

"No," they said together, and went back to their argument. Beckett sighed.

"Isn't there a murder somewhere that we could be solving?" asked Castle from his customary seat beside Beckett's desk.

"No, it's been quiet today."

"Hm."

A few moments' pause. Beckett sipped the coffee Castle had brought her. Then the phone on Beckett's desk rang. She picked it up. Castle looked on, appraisingly.

"Beckett," Kate spoke into the phone. After a moment, she looked up at Castle curiously.

"This guy says he wants to talk to my 'reporter' friend. I think he means you," she said, her hand over the mouthpiece, a confused frown on her face.

This stirred something in Castle's memory. Shrugging, he took the phone. "Castle," he said. Now Ryan and Esposito were looking over curiously.

"Hello, I'm calling to report a murder," said the voice on the phone. Castle frowned. Surely someone wouldn't need to talk to him to report a killing?

"Uh, okay," he said awkwardly, pressing the speakerphone button and beckoning to Ryan and Esposito. Beckett leaned forward.

"Where are you?" Castle asked the phone.

"What would be the fun of that?" said the voice. Castle's frown deepened. This reminded him of something. Or someone?

"Okay...," Castle said slowly. Ryan was gesturing for him to keep talking while he traced the call. "Who are you, then?"

"Oh, I'm a fan."

There was no doubt this time. Castle definitely remembered this. He looked up to exchange a concerned look with Beckett. She certainly looked worried.

"Uh, can you tell me more about the murder?"

"Well, I did it," said the voice, "and that's all you need to know."

The phone cut off.

"There's no way that's actually him," said Castle to the room at large, setting the phone down.

"I dunno, Castle, it sure sounded like him," said Ryan. "Anyway, we got an address... It's 42nd and Lex. Grand Central Station."

"It is him," said Beckett, shock visible on her face.

Castle ducked under the yellow caution tape, following Beckett to the place where Lanie crouched over the body.

"This is so surreal," said Castle, peering into an open phone booth, where the phone hung off the hook. It was like stepping back in time. Everything was the same, except -

"Our vic - male, early 40's - was shot four times, not five," said Lanie Parish, the ME. "So whatever message he has for us doesn't start with Nikki. Large entry wounds – the gun may have been a 45 or a 48."

"How did he get here, anyway? And where did he get the gun? I thought we locked him up with the state's most dangerous criminals," Beckett addressed Ryan and Esposito, who were conversing quietly in a corner, "and what're you two whispering about?"

Ryan gently avoided the second question. "Maybe he broke out. He doesn't seem the type to get outside help."

"But what were you whispering about?"

Ryan shifted uneasily and glanced at Esposito. Finally, Esposito spoke.

"Well, we were just wondering, if the bullets don't spell Nikki, what if they spell... Rook?"

Everyone turned and looked at Castle. Castle, who had been remarkably quiet this whole time, looked up from the victim's body and swallowed.

Back at the 12th, Castle was bending over an old case file at Beckett's desk. Ryan and Esposito were watching him nervously from across the room. Then Beckett walked in from her talk with Lanie. She addressed Castle.

"Well, the bullets do spell Rook. Gates has put a security detail on your place, so Alexis and Martha are okay." Castle nodded but didn't speak.

"Hey, you okay?" She looked at him with concern. He nodded.

"Liar. I know that look. That's the 'This is my fault' look." Castle grimaced.

"Come on, dude," said Ryan, who had walked over with Esposito. "You gotta quit blaming yourself for this nut-job."

Castle smiled despite himself.

"There you go," said Beckett, sitting down.

Just then, someone very familiar that they hadn't seen in a very long time walked in: Jordan Shaw, leading a group of people that they usually hated to see - FBI.

Everyone looked around. Jordan walked up to Beckett and held out her hand. Beckett took it, and shook.

"I'd say it's a pleasure to see you all again, but under the circumstances...," Jordan said, sounding a little resigned. "From what I've heard, though, Jameson Rook is the target this time." She looked at Castle. Castle glanced up at her and nodded mutely.

"Well, let's not waste time," Jordan said. They all stood and followed her to where her agents were setting up the war room.

"Based on the old case file, we can put together a good deal of information on our killer," Jordan explained, gesturing to the board, where an all-too-familiar face had just appeared. "He's a sociopath with a very high IQ, and he always needs to prove he's smart. He's a chameleon, changing his identity to become close to the victims. Thankfully that trick won't work now, since we know who he really is. He's also left-handed, though I think he'd have learned his lesson about that," she added with a glance at Castle. He nodded.

"But he'll know we know all this," Castle spoke a little hoarsely. "So he'll probably change his methods."

"Well, so far he's stuck to the old mo, given that he's still using bullets to send messages - and we have people watching the old crime scenes."

"But he won't kill there now that we know that, right?" said Beckett.

"Probably, but we still need to keep an eye out." Jordan went on, "We also know he likes to make a big scene-"

Castle flinched. "No kidding." He remembered watching Beckett's apartment explode terribly vividly.

"Do we know why he's doing this all over again?" asked Beckett.

"Could be he wants revenge on Jameson Rook for stopping him from killing Nikki Heat," suggested Jordan.

"Well, I guess you can blame yourself for saving Beckett's life, Castle," said Ryan sarcastically. Castle grinned reluctantly. Beckett gave Ryan a "really?" look.

"Finally," Jordan concluded, "we know Dunn doesn't leave fingerprints, because he burned them off when he was convicted of arson in '98."

"And we know he usually leaves bodies where he kills, but not always," said Castle helpfully.

"But how is any of this going to help us find him before he kills again?" Beckett wondered aloud.

"We'll start with the victim," said Jordan. "Maybe there's a significance." She tapped the board. "His name is Jim Wolffe." A picture of the victim appeared, next to-

"A list of arrests?" said Beckett.

"Was the victim a cop, or someone who got arrested a ton?" asked Castle.

"The latter, it looks like," said Jordan. "Maybe this guy was in prison with Dunn. Compare prison records." Files popped up on the screen.

"That's not it," said Beckett.

"Well, there's got to be something, or we wouldn't know where to start," said Castle, sounding frustrated, "and he likes to lead us on."

"Right. Compare the profiles of Scott Dunn and our vic." More files. Castle was reading them when his pocket vibrated. He pulled out the phone.

"Castle."

"Jameson. Did you get the first part of my message?"

Castle pressed the speakerphone button, exchanged a significant look with Beckett, and held out the phone for the room to hear.

"Yes, I did," Castle spoke with uncharacteristic coldness.

"Well, the next part is at the Central Park Reservoir," said Scott Dunn.

On the bank of the largest body of water in Central Park, the team, Jordan, and several FBI agents stood in a loose semicircle around Lanie, who was crouching by the victim.

"Uniforms searched the whole park. He's not here," said Beckett. Castle was standing beside her, looking down at the body.

"Female, mid-thirties, cause of death: two gunshot wounds in the upper torso," said Lanie. "The etching on the bullets have the letters 'I' and 'S'."

"Rook is... what?" said Ryan, startling Castle out of a thought by walking up behind him.

"No idea, but from Dunn's history, I'd say it can't be anything good," said Jordan grimly.

"Let's get the body to the morgue and get back to the precinct to find out what we can about our Jane Doe," said Beckett.

"The second vic is Maria Tracy, 36," said Esposito, reading off the smart-board. "She's a lawyer. She worked Scott's and Wolffe's cases, so there's our connection."

"That still doesn't tell us who he'll target next, though," said Castle frustratedly. "Does anything from the ME report strike anyone as unusual? Excepting the etched bullets, I mean."

"Well, there were traces of embalming fluid, so he's probably still making cyclonite, that explosive he used to blow up Beckett's apartment," said Ryan.

"Where did he get the embalming fluid?" asked Beckett.

"Maybe there was a break-in at a mortuary or a taxidermist's," suggested Castle. "Can we look up robberies in those areas? Maybe we can find something that will lead us to him from there." Jordan nodded to her partner, agent Avery, at the computer. A few rapid keystrokes, then a robbery file popped up.

"A load of embalming fluid went missing," said Beckett.

"As good as it is to know where he got the stuff, it doesn't much help us find him, or his next target," said Castle.

Officer Ann Hastings poked her head into the room.

"There's a man on the phone, asking for Jameson Rook," she said, her eyes on Castle.

Beckett, Ryan, Esposito, and Jordan followed Castle and Officer Hastings to the phone. Castle took it.

"Castle."

"Jameson, you'll have to work a little harder to catch me," said Scott Dunn smugly.

"Where are you?" asked Castle, tight-lipped.

"Well, I wouldn't tell you that. But I can tell you where you'll be within ten or fifteen minutes – the Museum of Natural History."

"Why would I be there?"

"Because the next part of my message is there too."

"Male, late 30's, two bullets to the chest - they're engraved with the letters 'I' and 'N'," said Lanie. "I can ID him once we get him back to the morgue." The team was scattered around in the parking lot of the museum.

Castle was frowning. Beckett noticed.

"What are you thinking?" she asked him. He didn't start out of his thought, but continued frowning, not at the victim, but at the signs along the street, reading "Museum of Natural History."

"I was just wondering, why these places? Is there something important about the locations of the murders?"

"Maybe he's trying to choose locations that are important to you. Didn't you tell me once that you used to come here with Alexis every Sunday?" Castle looked at her, surprised that she had remembered.

"I'd agree with you, but what about the other crime scenes? Grand Central Station and the Central Park reservoir?"

"Touché."

"Well, the last time he did this, one of the bodies was left at your front door. That was the third time he killed."

"But this is the third time he's killed now. So we don't know how likely that is anymore."

"All the same."

"Yeah."

They stood for a moment, wrapped in their separate thoughts. Then Jordan broke the silence.

"You two have been running flat out since the first murder. Go home and get some sleep."

"But-" Castle and Beckett both started to object.

"- No argument."

Apparently seeing the futility of their efforts, they left the scene.

"He's going to get himself killed."

Beckett was in her apartment, on the phone with her dad. She had just felt that she needed to talk to someone.

"He's not completely helpless, you know."

"Last time, Dunn had schematics of the precinct. What if he-"

"Castle's smart, Katie. It's his job to think like a killer, like it's your job, too."

"But he's not a cop."

"Think back. When has that ever stopped him from thinking and acting like one?"

Beckett thought.

"Exactly," said her father, not needing an answer.

Someone was knocking on the door at Castle's loft. He stood up from his seat in his study, walked over to the door, a bit apprehensive, and opened it.

"Beckett?"

She looked a bit awkward.

"What are you doing here?" he persisted.

She avoided the question. "Where's your security detail? There's no one outside your door."

"I sent them home."

She looked at him with an eyebrow raised. "Okay, it's one thing for me, an armed, trained cop to send home my detail. But you?"

"Do I detect actual concern for my safety?"

She avoided that question too. "Where are Martha and Alexis?" She peered around him into the loft. He realized he was being rude and gestured for her to enter, locking the door behind her.

"I sent them to the Hamptons."

"They went willingly?"

"No, but that's hardly the point."

They sat themselves at the kitchen counter. Beckett opened her mouth, but before she could get a word out, Castle spoke.

"Don't tell me to stop working this case, it won't work."

She closed her mouth. Something on his face must have told her that arguing was a waste of time.

"Well, I think I'll get up to bed," he said, a little awkwardly, gesturing toward the door for Beckett.

"No, I'm not leaving."

Castle raised his eyebrows.

"A psychopath is after you because you saved my life. I'm not leaving."

"Well, I guess that's fair," he said as Beckett settled herself on the couch, then he turned and walked up the stairs, smiling to himself.

Castle came downstairs in jeans and a t-shirt to find Beckett, making coffee.

"You're still here?"

"You sound so surprised."

"Well, to be honest, I thought you spending the night here was a dream." She threw a cloth napkin at him. He grinned that grin that made her blush. She turned back towards the coffee machine, hoping he hadn't seen, and he sat down at the counter, where she had laid out large plates of scrambled eggs and bacon. He remembered the first time she spent the night at his loft. It wasn't because she was willing; it was because Scott Dunn had blown up her apartment the previous day.

He also remembered that only two days before that occasion, he had stayed the night at Beckett's, because he had been concerned about Scott Dunn. He had gone to the door to get the paper, and a body had lain outside.

"What's the matter?" asked Beckett, who had seen him frowning.

"Well, maybe nothing, but... hold on," he said, and he stood up and walked to the door. Upon opening it, he jumped back. Sure enough, the body of a woman that had been left leaning against the door fell at his feet. He looked up at Beckett.

"Oh, not again," was the first thing she said.

"So, you had just gotten up, right?" said Esposito. He'd cornered Castle for "questioning".

"Yeah. Beckett had just finished with the coffee and I went to the door, and... yeah."

"Dude. She made you breakfast."

"So? I thought it was nice of her."

"That's not the point." Esposito was looking at him oddly.

"Oh, not this again. How many times do I have to tell you, there is nothing going on between Beckett and me."

"Sure." Esposito didn't even try to hide his skepticism.

Beckett was dealing with Ryan.

"Beckett... you made him breakfast?"

"Yeah, so? It's just breakfast."

"So, it's domestic."

Beckett glared at him. "We're done here."

Ryan moved on to pester Castle with Esposito.

"Dude. She made you breakfast."

"So I've heard." Castle sounded resigned.

"Details, Castle, details."

"I've told you this already. There are no details!"

"I can't believe you," said Esposito scathingly. Castle gave him a "whatever" look and walked over to where Jordan and Beckett were talking.

"This is serious déjà vu," he said as he approached them.

"No kidding," agreed Beckett. "Only this is a threat to you saying that Dunn knows where you live, not me."

"Point taken."

"You two can escort the body back to the morgue so Dr. Parish can pull the slugs," said Jordan.

"I don't think we're gonna live this one down," Castle said as Jordan walked away.

"I hear you two were at the loft when the body dropped," said Lanie predictably when they arrived at the morgue. Castle and Beckett exchanged exasperated looks.

"Nothing happened, Lanie," said Beckett.

"Sure," she said, sounding exactly like Esposito.

"So what about the bullets? Engraved like the others?" Castle changed the subject.

"Yep. Take a look."

Castle peered through the magnifying light attached to the examination table. The letters H, K, E, and two C's were neatly arranged in a row on the table. He rearranged them to form the word check.

"'Rook is in check?' What's that supposed to mean?" wondered Beckett.

"He means like chess," explained Castle. "It makes sense, really. The name Rook makes that kind of reference applicable in this kind of situation."

"I know that. But in check? What does he have planned? 'Rook is in check' is a lot less specific than 'Nikki will burn'."

"Well, we're not going to find out here. Let's get back to the precinct. You call Jordan and tell her the news."

"Right."

Lanie watched them go, shaking her head with a sigh, half-annoyed, half-amused.

At the 12th, half of the precinct was sitting around the war room, staring at the smart-board. Ryan, Esposito, and Avery were huddled around the computer, while Castle, Beckett, and Jordan were at the board, looking for a connection.

"This isn't like him," said Castle after a while. "He leads us, he never leaves us hanging. There's got to be something we're missing."

"I have to assume that since he doesn't have a patsy to kill, he'll go straight to his attempt at murdering his main target," said Jordan.

Beckett nodded. "Gates offered to have a security detail follow Castle. Of course, he refused," she said, glaring at him.

"It's not me I'm worried about," Castle stated flatly.

"We know that," Jordan interrupted Beckett before she could speak. "Is he always this stubborn?" she asked Beckett, one eyebrow raised at Castle, who was still staring at the board.

"No, usually he's worse," Beckett grinned halfheartedly, not exactly lying.

Castle, who was not listening, tapped the board and pulled up a map of the crime scenes. Something we're missing... no, it's not there. He dragged the map back into the file and brought out the profiles of the victims. Nothing.

"This isn't right," he mumbled. Beckett looked at him.

"What do you mean?"

"I-" he looked around the room as though the right words would manifest themselves there.

"It's... not how you would write it?"

Castle nodded and rolled his eyes, frustrated with himself.

Jordan was looking at Beckett, who gave her a "wait a second" look. Jordan nodded.

"Remember the last time that happened?" He nodded. "So what happens in your version?"

"He'd just be toying with us. The answer - he'd dangle it in our faces - taunt us. He'd call-"

And then the phone rang.

Beckett got to it first, but when she raised it to her ear, she handed it wordlessly to Castle, who sighed.

"Castle."

"Jameson, you're castling into it."

Castle frowned. "How so?"

"If I told you, you'd know, and we don't want that quite yet."

"Yet?"

"Of course. The showdown only works if it's just you and me."

"Tell me where you are," Castle spoke through gritted teeth.

Scott hesitated.

"... Will you come alone?"

Castle looked at Jordan and Beckett. Jordan nodded.

"Yes."

Scott seemed to recover himself from a moment of weakness.

"Sorry, Jameson, no hints for you and your friends."

The phone cut off.

"Did you get a trace?" Castle addressed Ryan and Esposito in a falsely casual tone.

"Uh... yeah," said Ryan as though coming out of a trance.

"It's an address in the Bronx," said Esposito. "1755 48th Ave."

"The same address where we found agent Shaw and Scott last time," confirmed Beckett, looking from Jordan to Castle and back.

Jordan nodded. "Let's go."

In the van, Beckett was frowning. Castle noticed.

"Something wrong?"

She didn't nod, but continued to frown, gazing into space. "What did he mean, 'castling into it'?"

"Castling is a move in chess where a player can move both the rook and the king at once. 'Castling into it' refers to when an inexperienced player castles because he can, not because he must, thus endangering his king." There was a hint of bitterness in his voice.

"Sounds like he thinks you're setting yourself up for something... like an ambush," said Jordan.

Now Castle was frowning, but he didn't have much time to think before the van pulled to a stop. Agent Avery was looking at one of the monitors in the van.

"Huh," he said, one eyebrow raised at the monitor, where a small red dot was blipping its way across the screen. "The signal from his phone is moving."

"What?"

Beckett leaned toward the monitor.

"Why would he lead us here, then run, but not turn the phone off?"

"I don't know, but that's him," said Avery.

"That can't be right, it's too easy. He wouldn't forget something like that," said Castle.

"Looks like he has - evidence speaks," said Beckett. "Anyway, he's getting farther away. Let's go."

She let Jordan lead the way out of the van, but when Castle tried to follow, she blocked him.

"Stay in the van."

"Yes, we've seen how well that works."

"Stay in the van, Castle. You're his target," and she shut the door on him.

She, Jordan and several FBI agents sprinted down the block in pursuit of a figure in a hoodie.

"Police, stop!" Beckett shouted. One of the agents knocked down the hoodie. "Wha - -?"

The agent pulled a phone from the guy's pocket.

"That's his phone, but this sure as hell isn't Scott Dunn."

The man had sandy hair and a curled mustache. Definitely not Scott Dunn.

"So where did he go?"

Beckett turned around in time to see Castle leaping out of the van in pursuit of a dark figure bolting out of an alley in the shadow of a building several yards back up the block.

At the end of the block, across the street, Scott disappeared through a heavy door into an old warehouse. Castle entered at full sprint and skidded to a halt, looking around for Scott, who had vanished. He heard the door slam behind him and spun around on his heels, but Dunn wasn't there.

Then he heard Beckett outside, trying to kick the door down, but it looked like it was made of steel.

"Beckett?" He pulled on the door. It wouldn't budge.

"Castle, are you okay?" She stopped kicking at the door.

"Yeah, I'm-," but then his phone rang.

"Checkmate, Rook."

There was a deafening bang and the sound of breaking glass as the windows of the warehouse shattered in the explosion. Beckett was nearly thrown of her feet in the force of the blast, and when she straightened up, the red glow of the fire in the building lit up the look of horror and disbelief spreading across her face.


End file.
